Document and Entity Information - shares	6 Months Ended
	Jun. 30, 2015	Aug. 01, 2015
Document And Entity Information [Abstract]
Entity Registrant Name	OPEXA THERAPEUTICS, INC.
Entity Central Index Key	0001069308
Document Type	10-Q
Document Period End Date	Jun. 30, 2015
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Is Entity a Well-known Seasoned Issuer?	No
Is Entity a Voluntary Filer?	No
Is Entity's Reporting Status Current?	Yes
Entity Filer Category	Smaller Reporting Company
Entity Common Stock, Shares Outstanding		53,387,743
Document Fiscal Period Focus	Q2
Document Fiscal Year Focus	2015